The Ultimate Video Game Crossover
by GamingKnight
Summary: A Halo/Dead Space crossover featuring Red vs. Blue. Halo's Flood and Dead Space's Necromorphs battle it out leaving the universe scarred, leading up to Halo's timeline. With the two threatening to return, the heroes of Halo, Dead Space, and Red vs. Blue must come together to help stop the impending Armageddon in its tracks. Disclaimer: I do not own Halo, RvB, or Dead Space.
1. Prologue

Prologue

For as long as humanity has existed, we have always pondered our origins. The number one question we have asked is why are we here. For what purpose? What reasons are we here? What is our destiny as a species? What will occur when this destiny is reached? The answers have always been there, buried under the rock and metal, time and space. With our restrictions, we've been unable to see these answers, never been able to answer the questions that eat away at our minds, which can keep some of us up at nights, thinking what the world would be like if we knew?

It's also worth pondering the questions as to if we are alone or not in this universe. Are we truely the only intelligent life forms in existance? If we aren't, where are the others? What is their role? What is everyone's role, and will we be ever able to carry it out? Or are we just a freak accident.

The answers hidden under rock and metal and time hide something terrifying. A horrifying origin of the universe and us, along with them. The answer is no, we are not alone, and no, we're not an accident. We evolve from something beautiful, but along with beauty, there must be an opposite.

The beginning showed the Forerunners, a vast, unique and evolved race. Advanced way beyond humanities own comprihension. That is seemingly why we went to war. Humanity and the Forerunners clashed upon their first meetings, a war which would scar the universe for ever.

The Forerunners hatched a plan to win the day, the first of the two Didacts taking control of the operation. Coping a plague that had struck in their earlier years, the Forerunners created the necromorphs, a horrible and disgusting outbreak that reanimated the dead to do the bidding of the one who could harness the powers of the artifact at the center, one to which they called Markers. The Didact used these markers to control earlier versions of the necromorphs, used to turn humanity against one another. He loved what he did, the blood shed and the killing, the sight of one human after another falling, only to come back as a horrid monster that would forever do his bidding until it fell a second and final time.

However, the Didact's wife, the Librarian, saw the darkness evolving around her husband, and went against his wishes, defying him. In an attempt to save as much as the human race as she could, she found that humanity wasn't just evolving, rising in an attempt to control the universe and gain power against them as the Forerunners previously thought, they were running.

Humanity's world had been destroyed and they had cast out into space in a desperate attempt to get away from the horror that followed, a parasite known as the Flood.

When the first of the parasite attacked following humanity, the Forerunners emerged victorious, as the Librarian herself took samples of the DNA of Flood to study in her labs along with many scientist in hope to find a weakness. An amazing discovery showed that it resembled necromorph codes, and that the cells of Flood and Necromorphs when put together would fight it out, cancelling each other out and each would disappear, defeated.

She showed her husband this discovery, though at first him and the Forerunner leaders disagreed with such a plan. But after world after another fell, their concern for decent and humane ways to deal with the problem decreased, and then dropped to none. Using the necromorphs, they sent their creating with a marker as tall as their tallest towers to the center of a Flood mass, where the necromorphs and flood battled it out, mutants killing each other all around, where each form of parasite and mutation would cancel each other out, just like the cells, and wouldn't leave another standing. The downside, however, was that the horrid battle that ensued wiped out all surrounding life, leaving a barren wasteland.

The Forerunner leaders made the decision not to use this strategy and to move on to other more desperate measures. During the planning, the Didact grew more hungry for war, and ignored their orders and continued the parasite war, sending the necromorphs out to battle the Flood over and over, with the same outcome each time. However, the necromorph outbreak grew more powerful each time, leaving a bigger void, much to the DIdact's delight.

Seeing her husbands evil ways grow, she tricked and imprisoned him in the leader's and her own creation, Requiem, and to the Librarian's wish, sealed it from the world so nor Flood or Necromorph would enter.

Unknown to any of them, the Necromorphs grew self aware, the Markers becoming their own minds. Their power became to uncontrollable, and with the exception of the Didact, any who mentally controlled them were utterally destroyed. It then became a three-way war, Flood vs Necromorphs vs Forerunner. In a desperate attempt, humans and Forerunners made an alliance to combat the two infections that were at their doorstep. This prooved to no avail.

While human and Forerunner lives were lost to the Flood and Necromorphs, they decided that if they waited for the two infections to wipe each other out, it would scar the universe to the point no significant life could ever be held again. The two species came to their most desperate decision, a deus ex machina of sorts. The Halo rings.

When crafted, each species had been worn down by the infecions to a point where barely any remained. The Forerunners made the Index, which would activate the Ark, the central hub of the rings to allow them to be set off all at once. Each ring was given its own activation index, in case of containment ever to be needed in any certain zone after the solution was carried out. The Forerunners, weakened to the point of no return, made the index only responsive to human DNA, so that when they would be able to contain the zones at any time needed afterward, when humanity had its chance to evolve once again to true intelligence.

After saying their goodbyes, the Ark was activated just in time, with Flood and Necromorphs at their heals, and the Halos did their job, wiping out all life which successfully starved the Flood, and the Necromorphs disappearing without a singe trace.

As humanity once again had the chance to evolve, the Necromorphs had recovered just as swiftly, growing smarter and larger. The outbreak was able to take moons of each conquered world as it slugged throughout the galaxies, until it eventually reached the milky way. Tau Volantis, an unfortunate planet, was the first to be hit, the necromorphs wiping out all life on that planet and taking away the moon, turning it into one of the many Bretheren moons. But in a last minute move, the race of that planet created a machine. That machine was able to freeze the planet with the outbreak still on it, stopping the necromorphs dead in their tracks, and making all the moons dormit.

The outbreak was revealed to a newly evolved human race, almost as if rediscovering them all over again, when one of the original markers the Didact used himself was found on Earth. Studied by key subject Micheal Altman, he and his fellow group of scientists were able to find out its true abilities, without learning its origins. With Earth dying and the marker effecting all humans on Earth, it pushed the group to hurry their efforts, accidently releasing the necromorph outbreak onto their underwater base.

Micheal Altman survived, but was captured and tortured for what he knew by EarthGov, until he was killed by a larger form of a necromorph as what they found as an appropriate form of punishment, and they used it to make Altman a martyr, creating the twisted religion of Unitology, which revolved around the markers.

A copy of the large black marker found on Earth was copied into a much smaller version of it, and was studied further on a remote colony named Aegis VII, where the outbreak showed its ugly face again, and forced the people there to hide away the marker and leave the outbreak dormit yet again on the planet as they fled, where it would be discovered 200 years later.

USG Ishimura mined up the marker after greedy eyes saw Aegis VII as a gold mine of mineals, including colbalt, silicon, ozmium, and so on. The marker yet again released its monstrousities as it was designed to, first making any residents in the area to go insane, and kill each other to the point where the bodies could reanimate into necromorphs, which spread to the ship.

When it went dark to the world, a rescue team including Engineer Isaac Clarke went to see what the problem was. After finding what the Ishimura held, all were killed except for Clarke, who was the first of any to successfully engineer his escape and destroy the local outbreak as he slammed the minded portion of the planet back in, wiping out Aegis VII and the red marker.

Afterward, he was captured and tortured similar to Altman for what he knew, only for the necromorph outbreak to reappear on Titan station, where he was held. Tiedmann, the runner of the station, used the codes in Isaac's brain to rebuild a large marker, which created the outbreak as a response, one he very well expected. Isaac escaped, found and killed Tiedmann, using the codes in his brain to destroy the second marker, and got away a second time, this time with one more survivor to the name Ellie Langford.

The events of Dead Space 3 took place shortly after, EarthGov being dismantled for its many violations to code, which included the Titan Sprawl incident. What remained went searching for Isaac Clarke, in response to an EarthGov team which had gone missing in Tau Volantis' orbit. Much to his dismay, Isaac tagged along, where Ellie, revealing herself to be with the team, told Isaac what hid under the snow on the ice planet. The two along with another key survivor, John Carver, and the rest of EarthGov went down to the planet. At the price of all but three, Carver, Isaac, and Ellie discovered that Convergence, a prophecy held dear to the Unitology religion, was actually the moons, which were made whole, and a key weapon held by the necromorphs. It acted as their minds, even controlling the Hive Minds, which Dr. Terrance Kyne of the Ishimura originally thought was the center of the monsters.

The three successfully destroy Tau Volantis' moon as it begins to wake, and Carver and Isaac are supposedly killed as Ellie successfully escapes.

At this time, the Gravemind is going through second stages of its development.

After arriving to Earth, Ellie Langford reports in her findings, and shortly after, begins consideration of suicide over her loss of Isaac. During this period, Isaac and Carver successfully return on a spare ship that orbited Tau Volantis. They come to discover that the remaining Bretheren moons have arrived to finish the job, unleashing the necromorphs onto Earth and killing off most of humanity.

A very few are put into cryo and stored away for a certain computer AI to awaken at a moment when they are needed, their knowledge key to what is needed to stop the outbreak should it ever return in the next cycle, if there is to be a next cycle. The rest are killed off very quickly, and when they saw no more food Earth had to offer, the necromorphs left once again without a trace. The moons grew quiet and slept, waiting for their next opportunity to strike once again.

The universe of the Halo series grew afterward, starting as always on planet Earth after it was able to successfully rebuild and heal after the events of Dead Space. Humanity evolved and populated more quickly, our minds very similar to the previous cycle, we built just like our previous selves.

Evolution was quicker, this time. We were able to gain star ships faster than any other of the previous cycles. With overpopulation becoming a concern, humanity cast out into the void of space, and was successful in finding what we were looking for. We began to colonize differant worlds, ones that even our past selves have never even heard of. Farming became a successful business as well, gaining nutritious minearals to carry us further.

War continued on though, as it always would. Humanity fought its own "civil war" as farmers rebelled to the more strict rules that the newly formed United Nations Space Corps had laid out. This war, however was cut short quickly.

As our expansion grew more, there was a point were it went too far. We ran into what once again answered the question as to whether or not we were alone, as a large union of alien races were found. Seeing us as a threat to their close-held religion, the Covenant, what they called themselves, launched a genocidal campaign against our race, taking us all by surprise as they hit a farming colony called Harvest. Over a period of five years, the war for Harvest had ups and downs before we were finally able to retake her, but at the lose of many men and women.

Realizing our mistake, we banded together as a species to strike back at the alien onslaught, but not before they became ruthless, taking one planet of ours after another in an effort to totally eradicate us.

A solution to this was found, as the SPARTAN II program had already been held as a replacement of its predecesor, considering the original SPARTAN candidates had experienced mass suicide due to their experiences.

The Spartan IIs were pitted against the Covenant, to great prevail, as the super soldiers slaughtered the aliens in almost ever battle scenario.

Originally designed for human rebellion, the program was seen as a huge success, and the details of its brutallity towards the candidates was forgotten since no one was conserned due to the fact that they were humanities greatest solution.

Then the Covenant hit Reach, a massive military base planet that many of the Spartans called home. Many assets were lost in the attack, including the UNSC's own Noble Team. Noble 03, Jun, was the only survivor of the team who was able to escape the planet and is now inactive. When the planet fell, many others didn't escape. Many of the Spartans were slain by the Covenant in their surprise attack, and only two were carried away on the UNSC Pillar of Autumn, captained by Jacob Keyes. The two were Chief Petty Officer Spartan John- 117, and Spartan Linda- 058, as well as a vital package, AI Cortana.

Critically wounded, Linda was placed in cryo, as was John (also known as Master Chief), and many of the remaining crew. When exiting jump-space, followed swiftly by the Covenant forces in pursuit of them, the two parties stumbled onto one of the Halo rings, where the Pillar of Autumn crash landed.

As the Master Chief stepped foot onto the Halo ring, the ruthless battle with the Covenant began, as him and the Autumn crew along with AI Cortana began learning the truth of the Halo, and its purpose.

While on the ring, Covenant forces entered a certain ancient structure belonging to the long extinct Forerunners, where they unintentionally stumbled into the Flood. Reawakened, mad, and hungry, the parasite escaped quickly and began its evolution process yet again. The Master Chief and Cortana discovered the true purpose of Halo, to wipe out all significant life to starve the parasite to the point of perishing. Deciding that's a fate the universe wasn't ready for, they destroyed the ring when overloading the Autumn's drive core, and escaped successfully via fighter jet.


	2. Prologue Pt 2

Over a period of a few months afterward, the UNSC discovered many more artifacts created by the same ancient species two cycles ago. During this period, the head of the Covenant, the Prophets, began to grow suspicious of their guardians, the Elites, whom showed signs of being unable to carry out their designated duties to the alien alliance. Casting them out, a civil war broke out, and the Elites eventually paired up with the UNSC, where the newly formed alliance stumbled upon the Ark. While pursuing the last Prophet, the Chief and the newly appointed Arbiter of the Sanghelei discovered that a new ring was being built to replace the old one destroyed months ago.

Making the hard desicion, with the Flood returning and spreading rapidly, the two fired the ring with Cortana's help, while it still being unfinished, resulting in the destruction of the Ark and the new ring. While attempting to escape the blast on the frigate Forward Unto Dawn, the portal they were passing through collapsed ontop of them, cutting it in half. The Arbiter made it back to Earth, while the Chief was left stranded in space, presumed dead.

Five years after the Halo event, Master Chief and Cortana were discovered by a rogue Covenant fleet, who still worshiped the idea of the "Great Journey". This forced them to crash land onto the metal sphere they orbited, Requiem, which is where they accidently reawaken the Forerunner leader, the Didact, the same who had been imprisoned for his use of the Necromorph onslaught to desimate humanity and the Flood.

Using his own most powerful weapon, the Composer, he was successfully able to escape Requiem and head to Earth with humanities own destruction in mind, but not before the Librarian was able to implant the Master Chief with the abilities to defeat him. He was proven to be successful, when he was able to defeat the Didact and destroy the Composer in Earth's orbit, with the help of Commander Lasky, an old friend of Chief's, and the UNSC Infinity, but not without the loss of AI Cortana.

After the events of Halo 4, the Flood from the farthest corners of the galaxy began to reform and re-evolve. It's hunger grew stronger than ever, and it had a more particular target than before, Earth. The old Gravemind from the events of Halo 2 and 3, who was able to survive the Halo detonation, was crippled and weak. Soon however, much like water, it would continue to move on, growing bigger and stronger until it reached its target.

Meanwhile, the Necromorphs began to reawaken, feeling that the cycle was ready for their return to once again feed upon the many worlds as it did cycles before. The two monstrousities grow nearer and grow hungrier, mortal enemies of themselves and of humanity as well. The war that will begin once they meet will be enough force to possibly wipe out the whole universe itself for good, unless someone strong enough rises to stop it.


End file.
